AS1170 datasheet(19/53 Pages) OSRAM

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AS1170

Detailed description

Datasheet

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• v2-00 • 2024-Feb-05

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across the current source is below low_vds6, the DCDC converter is stopped, the current

sources are disabled and the bit fault_ovp is set7.

7.5

Short circuit protection

After the startup of the DCDC converter, the voltage on LED_OUT1/2 is continuously

monitored and compared against VLEDSHORT if the LED current is above 14 mA8

(current_boost=0), 15.6 mA (current_boost=1)9. If the voltage across the LED (VFLED =

VOUT1/2-LED_OUT1/2) stays below VLEDSHORT, the DCDC is stopped (as a shorted LED is

assumed), the current sinks are disabled and the bit fault_led_short is set. In a dual LED

configuration for the AS1170, if a single shorted LED is detected, this LED is disabled and the

device continuous operation with the other LED.

Figure 18: Short LED detection

6 If overvoltage is reached, but none of the low_vds comparator(s) triggers, VOUT1/2 is still regulated below VVOUTMAX.

7 In constant voltage mode (5V generation, register bit const_v_mode=1) this fault is disabled.

8 Measured for each LED_OUT1/2 pin.

9 To avoid errors in short LED detection for LEDs with a high leakage current.

AS1170 数据表(PDF) 19 Page - OSRAM GmbH